Method for refining lead



2 p p 1,513,307 E. S. BERGLLJND I METHOD FOR REFINING LEAD Filed July 6: 1921 Ira/421222293 175.3613

now- Ami SALOMON BERGLUND,

Patented Oct. 28, 1924.

uN TaD STATES, PATENT ori ice."

or nJUnsnoLm, SWEDEN, ASSIGNOR TO 'TRoLLHA'r- TAHS ELEKTROTHERMISKA AKTIEBOLAG, OF STOCKHOLM, SWEDEN.

mmnon'ron REEINING Lam.

To all whom it ma3 concern:

Be it known' that I, EDWARD SALOMON BERGLUND, a subject of the lQing of Sweden,

residing at Djursholm, Sweden, have in-.-

vented certain new and useful Improvements in Methods for Refining Lead, for-which I have filed application in Sweden June 5, 1918, No. 2 75/1918, and of which the following isa specification.

For refining lead as a rule reverberatory furnaces have been employed fired with gas or coal. As a very high temperature is necessary for carrying out the refining operation a considerable amount of zinc and lead 'he collected in a common escapes from the lead hath during the said operation. On account of the great amount of combustion gases with which the metal vapours and oxides are diluted said gases must be subjected to a filtering operation in sack houses if it he required to free the gases from the metals and oxides contained therein, which operation is very costly and zrouhlesome.

In order to obviate these inconveniences the refining operation is carried out in an electric furnace according to the present invention. The advantage is thcreby'gained that the metallic vapours and oxides may condensation arrangement. Moreover, when electric current is employed as the heating means the refining o'peration willhe better controlled owing to the'easior manner in which the heat may be varied compared with when gas or a coal fire is'employcd.

For carrying out the ll)OVQ-(ltSCl'lllttl mclhod the device illustrated on the accompanying drawing may be employed.

1. indicates an electric smelting furnace with electrodes 2, an opening 3 for intro- Application filed July e, 1921 -Sertal No. 482,818.

' dueing the lead and device 4 for drawing off the refined lead. 5 indicates the escape of metallic vapours and 6 acondenser of any suitable type for vapours.

Through the 0 ning 3 which is provided with a shutter t e lead to be refined is introduced whereafter the same is smelted by admitting the electric current. By introducing air and steam tothe smelting cham ber zinc, tin, antimony and other volatile impurities contained in the lead are oxidized condensing said wherebysaid oxides together with some oxidized lead form a scum 0n the surface of the lead bath, which scum from time to time is withdrawn.

Having now described my invention, what I claim as'new and desire to secure by Letters Patent is 1. The method of refining impure lead, consisting in heating the lead by electric heat so as to volatilize impurities contained in the lead, condensing said volatilized im- 

